Reduction, Emergence, Etc.
This entry was posted on 8/20/2006 4:05 PM and is filed under Metaphysics.
In Ken Aizawa's simple (and in my opinion compelling) argument against the extended mind hypothesis applied to consciousness, he assumed that properties and relations of lower-level enties determine those of higher-level entities. In the comments, Adam Arico asked about emergence and Flora Carpenter further elaborated as follows:
Higher level states may have emergent features by virtue of their functional organization
that are not determined among lower level parts, and this higher level organization
(e.g. consciousness) uniquely influences the system.
Adam and Flora's question brings out some important themes in contemporary metaphysics of mind. I thought I'd add the following points to Ken's replies:
1. As Ken pointed out, the question of emergence is orthogonal to the conclusion of Ken's argument. Even if consciousness is emergent in the way described by Flora, it doesn't follow that consciousness "extends beyond the brain", as Alva Noe argued at the last Central APA.
2. The big debate about the relationship between higher and lower levels is usually between reductionism (e.g., Armstrong, Kim, David Lewis) and anti-reductionism (e.g., Fodor, Block). In this debate, "emergence" is usually employed to insult opponents (as in, "you anti-reductionists are nothing but a bunch of emergentists!" "No, we ain't!").
3. Emergentism was semi-popular in the early 20th century. But that was before the demise of vitalism. These days, few metaphysicians would want to get caught advocating the kind of emergence described by Flora. The reasons are quite simple: (a) vitalism is pretty dead; (b) where do the emergent features come from if not from the features of the constituents of the whole plus the way the constituents are organized? Speaking of "downward causation" from the whole's properties to its parts' properties sounds "spooky" and "magical" (I take terms in scare quotes directly from the literature), and no one seems to know how to tell a compelling philosophical story about it.
4. An interesting alternative to the traditional reductionism/anti-reductionism debate is the view held by C.B. Martin and John Heil (cf. Heil's book, From an Ontological Point of View, OUP, 2003). According to them, there is no issue of reduction vs. anti-reduction vs. (God forbid) emergence because there aren't any levels to reduce or emerge. There are levels of predicates and explanations, but not levels of properties. All properties and relations are fundamental; there are no higher level ones. And without higher level properties, the question of whether they reduce to or emerge from the lower level ones doesn't arise. Interestingly, Martin argues that there is still such a thing as emergence, but it's something that happens at the fundamental level, that is, the properties of the components may change once they are organized together in special ways. See his great paper, Martin, C. B. 'The Need for Properties: The Road to Pythagoreanism and Back', Synthese 112 (1997): 193-231.
are emergent if the were not deducible from properties of A and B in other systems. This means that the behavior of the parts in the system could not be predicted from their behavior in other constellations. 
. But since the space-limit, I will leave my objections to rest in peace.
